Such strips have been proposed under several forms. All of these, however, suffer from any of several serious drawbacks. Some are comprised of decomposing materials while others are easly clogged by the particles of soil and, still others, suffer from a reduced longitudinal or transversal permeability because of the pressure of the soil. Some allow too large a particle to pass. Some are too rigid and some are too weak.
This invention provides an easy to build, inexpensive, efficient structure in which all of the above drawbacks are eliminated.
It is to be understood that this new drain, although well adapted to the evacuation of water in a soil formation can also easily be used for a number of other applications in which the fluid exchange is from the soil towards the structure or vice versa.